MK Skymaster 20 build - Page 6 - RC Groups
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Oct 03, 2012, 08:32 AM
Why you type so loud?
Generic Member's Avatar
Pictures showing the shortened pipe and header.
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Oct 06, 2012, 12:33 PM
Registered User
doxilia's Avatar

good stuff!

That header is mighty short now. As you mentioned, hardly can be cut back any further.

It be interesting to try out a few different pipes and compare engine performance. I believe that Kato drew and used Hatori's original 200 series pipe which is pretty small and looks better suited to a 10-18 size engine. The 300's are about the size of a Mac 3.5 quiet pipe if memory serves. Pete kindly helped in obtaining both 200 and 300 pipes so I figured I'd eventually test the engine with each.

The muffled Mac's certainly fits with ample space though now that it's tuned. Will you be able to route the exhaust behind the TE former? Maybe a stinger extension?

Seems like paint and covering is all that's left to do! Maiden this Fall or next Spring? I guess you guys have better weather than we do up here...

Oct 07, 2012, 09:48 PM
Why you type so loud?
Generic Member's Avatar
I tried to bend some 7/16 OD aluminum tube with a spring tube bender. The first attempt with the thin wall material didnt turn out so well. The thick wall material produced accepable results as shown. Just a few grommets and a pipe mount away from completion. The rest of the airframe is ready for finishing.
Hopefully I will able to finish and fly it this fall.
Oct 08, 2012, 11:51 AM
Team Futaba
CSpaced's Avatar
Pipe looks good!
Oct 08, 2012, 11:55 AM
Registered User
doxilia's Avatar

Good stuff - done!

What did you decide for the wing finish? Trim painted white UC/MK? Maybe cover in transparent and paint everything?

Oct 08, 2012, 01:09 PM
Why you type so loud?
Generic Member's Avatar
The wing finish will be Monokote with Monokote trim. I have color matching KlassKote for the fuse.

Design will be similar to the box art. Not quite sold on what I came up with for the bottom.
Last edited by Generic Member; Oct 08, 2012 at 02:51 PM.
Oct 08, 2012, 09:32 PM
AndyKunz's Avatar
I like sunbursts on the bottom of my models.

Oct 09, 2012, 12:38 AM
Registered User
Jeff, lovely work!!

I like the first one because the bottom gave better contrast. I remember flying the MK Aurora and Curare 25s on pipe. They were small and ballistic and so hard to see.

Have you seen Hanno's scheme for the bottom on the Curare/Magic? It was a simple large horizontal stripe across the wings (with some thin trim) and provided great contrast.

btw did I see HS-82MGs? For some reason I've had great luck with 85MGs but horrible luck with the 82MGs. They just don't center well for me even with perfect smooth ball linkages. They would drift off center constantly which I imagine would be annoying on the elevator of a small pattern plane. Just a heads up in case you're using them...

Can't wait to see the paint!

Oct 09, 2012, 09:24 AM
Why you type so loud?
Generic Member's Avatar
Ohhh Matt, say it isn't so. I'm so fed up with Hitec servo's and their dodgy centering. I haven't used HS-82's on control surfaces so I don't have first hand experience with the accuracy of their centering, but based on your feedback and my experience with other Hitecs, I'll use something different for the control surfaces and unload my remaining stash of HS-82MG's. I guess I'll be shopping for some Airtronics 94819's.

If I can find a bottom wing design I like, then I'll start Monokote this week.

Found the Airtronics 94819's for $20 direct from Airtronics.- Best price on the web. Tower has them for $39.99.
Last edited by Generic Member; Oct 09, 2012 at 09:40 AM.
Oct 09, 2012, 12:18 PM
Registered User
doxilia's Avatar
Hmm... this HS82 news is disturbing, I have a small handful that was planning to use in similar applications. After bench testing them and comparing them to the Hobbico CS110 digitals (now also branded under the Tower servo name), the latter are clearly superior.

Jeff, those Aitronics do look interesting and have a good price too. Are they not a fair bit larger than the slim servo's above?

Oct 09, 2012, 12:56 PM
Why you type so loud?
Generic Member's Avatar
They're 4mm wider and about 2mm longer. I have penty of room in the servo plate to make the adjustment.

FYI: This is a VERY cool website:
Last edited by Generic Member; Oct 09, 2012 at 01:02 PM.
Oct 09, 2012, 03:05 PM
Raised on 80's Pattern
Fatherof4's Avatar
I am using these on for the Ailerons on my Conquest IV:

Airtronics 94819 Mini Digitals - Super fast and light - 33 oz of torque

I have been very happy with them.

Oct 09, 2012, 04:26 PM
Why you type so loud?
Generic Member's Avatar
Thanks for the feedback Doug. I ordered a set for the Skymaster.
Oct 09, 2012, 06:38 PM
Registered User
Jeff based on my experience I would say you made a great choice to change them and well worth the investment! I just can't stand servo drift in pattern planes. Especially a nice rare kit built vintage like your Skymaster!

I first used the 82MGs in the Fliton Element, a 30 sized electric pattern plane. Linkages are perfect. Servos would drift off center ever so slightly during flight requiring me to constantly re-trim one click on elevators or ailerons which bugged the hell out of me!! Changed to 85MGs, all is perfect and locked in. Then I tried the 82MGs on a Matt Chapman Cap 580, the same thing requiring me to trim back and forth in flight. Drives me crazy! No more 82MGs for me.

The 94819s looks good and great price! Hobby People also sell them for $19.99. 33oz should be enough for the 25 size plane, and fast! You can use short arm on servo and slightly longer horn on control surface give more leverage/torque. I used the similar size Airtronics 94761/762 a lot in competition sailplanes and they are rock solid and center superb.
Oct 09, 2012, 11:49 PM
Registered User

Exhaust diverter

Jeff, can you describe what size of aluminum tubing you use for the exhaust diverter and how you bent it? Did you heat it or just bent it with the coil?

Is it this one from K&S, 7/16" diameter 0.035" thick?

I am thinking to do the same on my Arrow. The pipe currently points straight at the tail. It looks cool but gets very messy. I will have to bend the tubing at an offset angle to one side of the fuse to clear the pushrods, exactly as you did. How did you secure the diverter at the bottom?

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